1. Field of the Invention
The present invention is related generally to a transversely excited waveguide laser having at least one discharge channel and two cooling channels arranged symmetrically thereto in a rod of insulating material.
2. Description of the Related Art
A transversely excited laser is disclosed in German published application No. 35 04 403 and corresponding Great British application No. 2,154,788. In a rectangularly profiled rod of ceramic are found in seperate grooves, a discharge channel, electrodes at both sides of the discharge channel, and cooling channels outside the electrodes. The grooves are covered with a cover member of rectangular cross section. The disclosed structure is poorly suited for high power lasers since the cooling of the discharge channel occurs over a relatively long path around the electrodes, resulting in a high temperature gradient in the ceramic. Since the structure is thermally asymmetrical relative to the discharge channel, bending of the ceramic rod can result, thus leading to a considerable reduction in laser power.
In German published application No. 33 27 257 and corresponding U.S. Pat. No. 4,620,306 is disclosed a transversely excited gas laser having a discharge channel of ceramic at whose outside wall metallic electrodes are applied. Cooling channels are formed in the electrodes. This device does not completly match the temperature coifficients between the cooling channel and the discharge channel. Since the matching of the temperature is coefficients is valid only for a specific temperature range even for optimally matched metals, thermal stresses cannot be entirely avoided.
In German Pat. No. 30 09 611 and corresponding Great British Pat. No. 2,071,904 is disclosed a method for manufacturing a waveguide laser member having a laser capillary and cavities radially connected thereto which is manufactured by an extrusion method. The cavities serve as supply reservoirs for the laser gas.
German Pat. No. 30 39 634 discloses the same form of laser waveguide member. The laser capillaries and cavities, however, are manufactured by a schoopage method. According to this patent, the cavities which are radially spaced from the discharge space should, amoung other things, also be used as cooling channels. The extruded embodiment, however, cannot be manufactured with the precision required for high efficiency.